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/*! \internal \file
 * \brief Defines helper functionality for device transfers for tests
 * for GPU host allocator.
 *
 * \author Mark Abraham <mark.j.abraham@gmail.com>
 * \author Paul Bauer <paul.bauer.q@gmail.com>
 */
#include "gmxpre.h"

#include "gromacs/gpu_utils/device_context.h"
#include "gromacs/gpu_utils/hiputils.h"
#include "gromacs/hardware/device_information.h"
#include "gromacs/utility/arrayref.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/gmxassert.h"
#include "gromacs/utility/stringutil.h"

#include "devicetransfers.h"

namespace gmx
{

void doDeviceTransfers(const DeviceContext& context, ArrayRef<const char> input, ArrayRef<char> output)
{
    GMX_RELEASE_ASSERT(input.size() == output.size(), "Input and output must have matching size");
    hipError_t               status;
    const DeviceInformation& deviceInfo = context.deviceInfo();

    int oldDeviceId;

    status = hipGetDevice(&oldDeviceId);
    checkDeviceError(status, "Error while getting old device id.");
    status = hipSetDevice(deviceInfo.id);
    checkDeviceError(status, "Error while setting device id to the first compatible GPU.");

    void* devicePointer;
    status = hipMalloc(&devicePointer, input.size());
    checkDeviceError(status, "Error while creating buffer.");

    status = hipMemcpy(devicePointer, input.data(), input.size(), hipMemcpyHostToDevice);
    checkDeviceError(status, "Error while transferring host to device.");
    status = hipMemcpy(output.data(), devicePointer, output.size(), hipMemcpyDeviceToHost);
    checkDeviceError(status, "Error while transferring device to host.");

    status = hipFree(devicePointer);
    checkDeviceError(status, "Error while releasing buffer.");

    status = hipSetDevice(oldDeviceId);
    checkDeviceError(status, "Error while setting old device id.");
}

} // namespace gmx
